https://gup.ugal.ro/ugaljournals/index.php/mtd <p style="margin: 0cm; margin-bottom: .0001pt;"><strong>DOI:</strong> <a href="https://doi.org/10.35219/mtd" target="_blank" rel="noopener">https://doi.org/10.35219/mtd</a></p> <p style="margin: 0cm; margin-bottom: .0001pt;">ISSN-L <span style="color: windowtext; text-decoration: none; text-underline: none;">2247-9635</span> ; ISSN <span style="color: windowtext; text-decoration: none; text-underline: none;">2247-9635</span></p> <p style="margin: 0cm; margin-bottom: .0001pt;"><strong>Frequency:</strong>&nbsp;quarterly</p> <p style="margin: 0cm; margin-bottom: .0001pt;"><strong>Subjects covered:</strong> testing and diagnosis of machine elements, materials and design solutions from the mechanical point of view</p> <p style="margin: 0cm; margin-bottom: .0001pt;"><strong>Contact:</strong>&nbsp;lorena.deleanu@ugal.ro</p> Galati University Press en-US Mechanical Testing and Diagnosis 2247-9635 <p>All rights are reserved for this publication, which is copyright according to the Romanian law of copyright. Excepting only any fair dealing for the purpose of the private study, research, review, comment and criticism, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, mechanical, electrical, electronic, optical, photocopying, recording or otherwise, without the prior express permission of the copyright owners.</p> https://gup.ugal.ro/ugaljournals/index.php/mtd/article/view/6149 <p>With the emergence of winglets, especially aerobatic gliders, have considerably improved their aerodynamic performance by increasing lift and aerodynamic fineness. Winglets bring a benefit to the evolution of aerospace engineering and are now used on as many aircraft as possible. In addition, the implementation of the winglet with corrugations, circular or sinusoidal in shape, can be an important step in aviation development by reducing drag, which in turn increases lift. In this paper, three types of wing configurations have been designed, CFD analysed, manufactured by additive technologies and three-point bend tested, namely: conventional, circular leading edge and sinusoidal leading edge. In aerodynamic tests the sinusoidal wing showed a higher lift coefficient at negative angle of attack and zero angle of attack, while the circular wing showed better performance at positive angle of attack. From the mechanical tests, of the three 3D printed wing configurations, the conventional wing showed the highest bending strength and the highest strength to mass ratio.</p> Alexandra-Ioana STROILESCU Sebastian-Marian ZAHARIA Mihai-Alin POP ##submission.copyrightStatement## 2023-04-11 2023-04-11 13 1 5 10 10.35219/mtd.2023.1.01 https://gup.ugal.ro/ugaljournals/index.php/mtd/article/view/6192 <p><em>These days, information on water quality is essential for furture activities related to water: water as a source of drinkable liquid, water as industry supply for many technologies, but also water as a balance component of ecosystems. This is why, this paper presents several characteristics for the water sampled from Prut River and a discussion of the measured values. Based on the survey during the year 2022, the following conlcusions on water of river Prut could be drawn. Prut river has particular evolutions of its characteristics due to its geographical position and specific climate. The&nbsp; dependences of analyzed characteristics mainly on seasons reflect that human activities is not yet dominant in modifying these parameters. The role of Prut river as water border between Romania and Moldova should be taken into account when analyzing the data presented in this paper, as many human and agricultural activities around rivers are of low intensity as compared to internal water.</em></p> Dinu GÎRNEȚ George Ghiocel OJOC Lorena DELEANU ##submission.copyrightStatement## 2023-04-11 2023-04-11 13 1 11 18 10.35219/mtd.2023.1.02